Older adults identified as frail are at significantly greater risk than non-frail older adults for mortality, hospitalization, falls, worsening disability, nursing home admission, postoperative complications, depression, and fractures. The prevalence of frailty is thought to increase with age with approximately 6% of those age 65 and older, 18% of those age 75 to 84, and 36% of those age 85 and older classified as frail. Frailty is conceptualized as a state of enhanced vulnerability to stressors such as illness and is attributed to the accumulation of dysregulation in multiple physiological systems. The causes of frailty are not known, but much focus has been given to understanding the biological factors associated with the condition with particular emphasis on the role of inflammation. Biomarkers of inflammation have been found to be significantly higher in frail versus non-frail individuals. A few studies have also examined the role for psychological factors in relation to frailty and have found that poor psychological well-being (PWB) is significantly correlated with the presence of frailty and enhanced PWB can have a protective effect against the development of frailty over time. Evidence has also supported a relationship between inflammation and PWB in that individuals with enhanced PWB have been found to have lower levels of inflammatory biomarkers. Sociodemographic (e.g., gender) and health (e.g., comorbidities) factors have also been identified as correlates of frailty in older adults. However, no study has examined these factors together, particularly inflammation and psychosocial well-being, in regard to frailty in older adults. A bio-psychosocial approach to the study of frailty allows for a more comprehensive understanding of how various factors (e.g., biological, psychosocial, sociodemographic, and health) relate to and influence frailty. The purpose and short-term goal of the proposed study is to examine how inflammatory biomarkers, sociodemographic and health characteristics, and psychosocial well-being are related to frailty and to each other in older adults. A secondary data analysis of data from 239 adults age 65 years and older from the longitudinal National Survey of Midlife Development in the United States (MIDUS) will be used. The specific aims are to: 1) describe the bio-psychosocial profiles of non-frail, pre-frail, and frail older adults;2) To examine the influence of Time 1 PWB, sociodemographic and health characteristics;Time 2 PWB, and change in PWB over time on frailty classification at Time 2;and 3) examine the role of inflammatory markers as a mediator of the relationship between psychological well-being and frailty classification. The proposed study is an opportunity to gain a comprehensive understanding of frailty that has the potential to advance the science on frailty and highlight avenues for future nursing interventions. This study will also lay the foundation for the applicant's program of research that will incorporate a bio-psychosocial approach to studying the ways in which the health and well-being of frail older adults can be improved. PUBLIC HEALTH RELEVANCE: Older adults identified as frail are at significantly greater risk than non-frail older adults for mortality, hospitalization, falls, worsening disability, nursing home admission, postoperative complications, depression, and fractures. Frail older adults are a vulnerable group of individuals who face challenges in trying to maintain their health and independence and also pose a challenge for caregivers and health professionals attempting to understand and treat the complicated array of factors that may contribute to frailty. The prevalence of frailty increases with age and with the number of adults age 65 or older expected to reach 72 million by 2030, the prevalence of frailty can only be expected to increase and its negative impact on the health and well-being of such a large proportion of the United States population make frailty an important public health issue.